Handrail, scaffold, method of erecting a scaffold and use of a handrail in a scaffold

ABSTRACT

A guardrail for a scaffold, which has at least at one end a coupling section for coupling with a coupling element of a vertical post or vertical frame of the scaffold, wherein the coupling section is flat and is penetrated by an elongate opening which extends parallel to a longitudinal axis of the railing member and which has a constant width as far as an extension at the end. 
     A scaffold comprising a guardrail, a method for erecting a scaffold and a use of a guardrail.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of German Patent Application No. 10 2021 109 947.1 filed on 20 Apr. 2021, the entire content of which is incorporated herein by reference.

FIELD

The invention relates to a guardrail spar for a scaffold and to a scaffold comprising a guardrail spar according to the invention. In addition, the invention relates to a method for erecting a scaffold and to a use of a guardrail spar according to the invention in a scaffold.

The term “scaffold” may refer in particular to a modular or frame scaffold.

BACKGROUND

Modular and frame scaffolds comprise prefabricated, standardized scaffold components that enable the scaffold to be erected and dismantled quickly, for example for scaffolding a building façade. Frame scaffolds have prefabricated vertical and horizontal frames. Modular scaffolds comprise individual vertical standards and horizontal beams that can be assembled into complex area or room scaffolds using standardized connecting elements and/or connection nodes. Since scaffolds usually comprise several scaffold levels, fall protection is provided in the form of guardrails. If the scaffold is still being erected, there is no fall protection until the guardrail is assembled.

In the prior art, therefore, dismountable scaffolds with a so-called “leading guardrail” have already been proposed. In the case of a leading guardrail, the guardrail rail of the next scaffold level is erected from the level below, namely in front of the floor covering. If the floor covering then follows, the guardrail is already in place. In this way, safety is increased when erecting a scaffold with several scaffold levels.

A method for assembling and disassembling a dismountable façade scaffolding, in which the railing is designed as a leading railing, is exemplified in the disclosure document DE 196 33 092 A1. In order to assemble a railing element, which belongs to a scaffolding level to be erected, in time before the floor slabs of the scaffolding level to be erected, the railing element is coupled at one end to a support element already assembled in the region of the scaffolding level to be erected, and at the other end to a further support element not yet assembled. During the assembly of the further support element, the guardrail element is then swivelled into a horizontal position and thus brought into its final position.

The publication document DE 101 11 976 A1 provides an example of a method for mounting a plurality of railing elements in a storey of a scaffold, in which the railing elements have engagement means at their ends for engaging in a perforated rosette connected to a vertical support. These engagement means are hook- or claw-like, such that they allow the railing elements to pivot unilaterally in engagement with a perforated rosette relative to the vertical support comprising the perforated rosette. The perforated rosette defines the fixing position of the railing elements.

The present invention is based on the task of simplifying the assembly and disassembly of a guardrail rail during the erection or dismantling of a scaffold. At the same time, suitable coupling means are to be used to ensure that the guardrail rail cannot be dismantled without further ado in the installed position, i.e. in its final position of use, but only successively when the scaffolding is dismantled.

To solve the problem, a guardrail spar and a scaffold as well as the method for erecting a scaffold are proposed. Furthermore, a preferred use of a guardrail spar according to the invention in a scaffold is indicated.

SUMMARY

A guardrail spar for a scaffold is proposed, which has at least at one end a coupling portion for coupling with a coupling member of a vertical post or vertical frame of the scaffold. The coupling section is flat and has an elongated opening extending parallel to a longitudinal axis of the guardrail spar, the opening having a constant width up to a widened end.

The guardrail post can be connected to a coupling element of a vertical post or vertical frame by hooking it in via the widened opening at the end in the coupling section. The widened end eases to hang or thread the coupling element into the opening of the coupling section.

Furthermore, due to the different widths of the opening, a positive connection can be achieved between the coupling portion of the railing spar and a coupling element of a vertical stile or vertical frame. However, this requires that the coupling element of the vertical stile or vertical frame has a bead-like protrusion, for example is shaped like a mushroom head. In this case, the coupling element forms an undercut area which can be engaged behind by the coupling section of the railing spar. The coupling portion is then engaged via the end extension of the opening, which for this purpose is preferably guided up to a lateral edge of the coupling portion or has dimensions adapted to the dimensions of the bead-like projection. The coupling section thus passes behind the bead-like projection of the coupling element when it is hooked in. The positive fit is subsequently achieved by displacing the coupling portion relative to the coupling element, so that the coupling portion engages behind the bead-like projection. For this purpose, the width of the opening is preferably adapted to the width or diameter of the coupling element beyond the bead-like projection.

The positive fit between the coupling section of the railing post and the coupling element of the vertical post or vertical frame prevents the railing post from being unhooked in its end or use position. This is because, in order to be unhooked, the railing post must first be moved again, which is not possible as long as the railing post is coupled to two assembled vertical posts or vertical frames.

The fact that the opening of the coupling section is elongated makes it possible to move the railing spar relative to a coupling element of a vertical post or vertical frame. Since the opening extends parallel to the longitudinal axis of the railing spar, the railing spar is displaced in the longitudinal direction. The railing spar may be oriented horizontally or at an angle. Depending on the specific design of the coupling element, in addition to the displacement, a twisting and/or pivoting may be required in order to transfer the railing spar into its end position or position of use.

In the top view of the coupling section, the elongated opening and/or the end-side extension of the opening is/are preferably arranged centrally with respect to the longitudinal axis of the railing spar. Accordingly, the longitudinal axis of the railing spar also forms the longitudinal axis of the opening and/or the extension. On the one hand, this facilitates the manufacture of the guardrail spar. On the other hand, no axis offset has to be taken into account when assembling the scaffold.

To form a guardrail, the proposed guardrail post is mounted at the height prescribed for fall protection. However, the proposed guardrail post may also be used to form knee rails. For this purpose, only the guardrail rail needs to be mounted at the height of the knee rail.

According to a first preferred embodiment of the invention, the end extension of the opening of the coupling section is arranged at the end of the opening that faces the railing spar. The end facing the railing spar is the inward end of the opening. At the outer end or end facing away from the railing spar, the opening thus has a width that is smaller than the width of the extension. After hooking in, the railing post is thus displaced in such a way that the coupling element passes from the widened inner end to the outer end of the opening, which is not widened.

Provided that the inner end of the opening of the coupling section is widened, it is further proposed that the opening is widened only on one side. That is, the end-side widening extends only towards one side or is arranged asymmetrically. Thus, in the top view of the coupling section, a substantially L-shaped opening is obtained.

Furthermore, preferably, in the top view of the coupling section, the end-side widening of the opening is guided in a slot-like manner up to a side edge of the coupling section. The slot-shaped extension open towards the lateral edge simplifies the hooking-in of the coupling section, in particular in the case of a coupling element of undercut design, since the coupling section does not first have to be guided over a bead-like projection, but can be hooked in immediately behind the bead-like projection.

According to another preferred embodiment of the invention, the end extension is arranged at the end of the opening that faces away from the railing spar. The end facing away from the railing spar is the outer end of the opening. At the inward end or end facing the railing spar, the opening thus has a width that is smaller than the width of the extension. After hooking in, the handrail is displaced in such a way that the coupling element moves from the widened outer end to the inner end of the opening, which is not widened.

Provided that the outer end of the opening of the coupling portion is expanded, it is further proposed that the opening is expanded on both sides. That is, the end extension extends on both sides of the opening. In particular, the extension may be arranged symmetrically with respect to the opening. Preferably, the opening and the extension are formed in mirror symmetry with respect to the longitudinal axis of the guardrail.

In a symmetrical arrangement of the extension, the extension cannot be guided to a side edge of the coupling portion. Accordingly, the coupling section cannot be hooked directly behind a bead-like projection of a coupling element, but must first be guided over the bead-like projection. The size and shape of the end extension is therefore preferably adapted to the size and shape of the bead-like projection.

Preferably, the coupling member of the vertical post or vertical frame has a circular cross-sectional shape as this allows the guardrail to pivot easily about the coupling member.

As a further measure, it is proposed that in the top view of the coupling portion the end-side extension of the opening is rounded, in particular circular or part-circular in shape. The rounded shape of the end-side extension also contributes to the fact that the railing member can be easily pivoted about the coupling member.

Irrespective of the specific design and arrangement of the end extension, it is therefore proposed that the outer end of the opening is rounded in each case, in particular circular or part-circular in shape. A simple pivoting of the railing spar is thus always ensured. This is particularly advantageous when forming a forwardly extending guardrail, since here the guardrail spar is pivoted in order to transfer it into its position of use.

Depending on the specific design of the coupling section and/or the coupling element, the railing spar not only has to be pivoted during assembly, but may also have to be rotated. This is particularly the case if the end extension of the opening is not guided up to a side edge of the coupling section. Moreover, if the coupling element is L-shaped, the coupling section must first be aligned horizontally or at least approximately horizontally in order to thread the coupling element into the opening. Subsequently, the railing member must be rotated about its longitudinal axis or an axis parallel thereto so that the coupling section is transferred from the horizontal position to a vertical position.

The space conditions in the area of the coupling element can be so much constricted that little space is available for turning the railing spar. Preferably, therefore, the coupling section has a reduced width at its end facing away from or outwardly of the railing member. To reduce the width, preferably the coupling section has a recess on both sides so that the coupling section is mirror-symmetrical with respect to the longitudinal axis of the railing spar.

It is further proposed that the coupling portion has, in top view, an arcuate end edge connecting the side edges of the coupling portion. The coupling section may, for example, be formed as a tab rounded at the end. The rounded end facilitates pivoting of the railing member about the coupling element after it has been hooked in. This applies in particular if the end edge of the coupling section, which extends in the shape of an arc of a circle, is arranged concentrically to a rounding at the outer end of the opening, so that the coupling section has the same width all round in the region of the opening. This ensures that the coupling section does not strike anywhere when pivoted. The rounding at the outer end of the opening can be both a rounded end and a rounded end extension of the opening.

The railing rail is preferably made of a metal tube, as this has a high rigidity and thus stability. At the same time, weight can be saved because the tubes are hollow. Furthermore, the metal tube preferably has a circular cross-sectional shape. Thus, no risk of injury emanates from the guardrail. Alternatively or additionally, it is proposed that the railing spar is plastically deformed at least at one end, for forming or receiving a coupling section. The plastically deformed end portion creates a transition from the flat coupling portion to the metal tube. In addition, the railing spar requires less clearance for movement during pivoting.

At this point it is pointed out that the coupling section and the railing spar can be manufactured in one operation or separately and then joined.

The proposed guardrail spar preferably has a coupling section at each of its two ends. With the aid of these, the guardrail rail can be arranged between two vertical posts of a modular scaffold or two vertical frames of a frame scaffold and fastened to them. The two coupling sections may have the same or different configurations. Specific examples of embodiments are described in more detail below.

Furthermore, a scaffold, in particular a module or frame scaffold, having at least one guardrail spar according to the invention and at least one vertical post or vertical frame is proposed. The vertical post or vertical frame comprises at least one coupling element for coupling with a coupling portion of the guardrail spar. The guardrail spar according to the invention simplifies the structure of the scaffold. Furthermore, it enables the formation of a forwardly extending guardrail. Depending on the specific design of the coupling element of the vertical post or vertical frame, it is also possible to achieve a positive fit between the coupling section of the guardrail spar and the coupling element of the vertical post or vertical frame, which prevents the guardrail spar from being dismantled in its position of use, that is to say when the scaffolding is fully erected. This increases the safety of the scaffold.

To increase safety, it is not necessary for each guardrail spar to be designed in accordance with the guardrail spar of the invention. A guard-railing post according to the invention at the beginning and at the end of a scaffolding level is sufficient to secure further standard guard-railing posts of the same scaffolding level. This means that standard guardrail rails can continue to be used.

According to a preferred embodiment of the invention, the coupling element is substantially L-shaped and has a first section connected to the vertical stem or the vertical frame and a second section arranged at an angle, in particular at right angles thereto, which preferably extends vertically upwards in the position of use of the vertical stem or vertical frame. The second section thus preferably runs parallel to the vertical stem.

Due to the L-shape, the coupling element forms a kind of hook. This is open towards the top, so that in the position of use of the guardrail rail the coupling section cannot be unhooked without lifting, i.e. without the application of external force. This is particularly true with respect to a coupling portion having an opening whose end extension does not extend to a side edge. This is because, in this case, the coupling portion needs to be lifted not only over the horizontal first portion of the coupling member but also over the vertical second portion.

In a further development of the invention, it is proposed that the first section and the second section of the coupling element each have a circular cross-sectional shape. Preferably, the diameter is selected to be slightly smaller than the width of the opening of the coupling portion of the guardrail. Alternatively or additionally, it is proposed that the second portion comprises a bead-like projection. The bead-like protrusion forms an undercut region, which can be engaged behind by the coupling portion of the railing spar. To form the bead-like protrusion, the second portion of the coupling member may be configured to be mushroom-headed, for example. As a result of the coupling portion engaging behind the bead-like projection in the use position of the guardrail rail, it is impossible for the guardrail rail to become unhinged. This is because the bead-like projection cannot be overcome without displacing the guardrail rail. In the position of use of the guardrail rail, however, displacement is not possible.

In a further development of the invention, it is proposed that the bead-like projection extends over only a partial circumferential region of the second portion of the coupling element. This facilitates the threading of the coupling element into the opening of the coupling portion of the guardrail spar, in the region of the end widening of the opening, during assembly of the scaffold.

Advantageously, the bead-like projection is arranged at least on the side of the second portion of the coupling element facing the vertical stem or the vertical frame, so that the distance between the second portion of the coupling element and the vertical stem or the vertical frame is reduced by the projection. In this case, the distance between the second portion of the coupling element and the vertical post or the vertical frame may be so narrow that the coupling portion does not fit therethrough in a horizontal position without a previous displacement of the guardrail rail. Unintentional disassembly of the guardrail post can thus be made even more difficult.

For solving the task mentioned at the beginning, further a method for erecting a scaffold, in particular a modular or frame scaffold, is proposed. In the method, a guardrail according to the invention is connected to a first vertical post or frame already assembled and to a second vertical post or frame still to be assembled. The method comprises the steps of:

-   (a) coupling a first coupling portion of the guardrail rail to a     coupling member of the first vertical post or frame, -   b) coupling a second coupling portion of the guardrail rail to a     coupling member of the second vertical post or frame, -   c) positioning the guardrail rail by means of the second vertical     post or frame, which is moved into its position of use for this     purpose, the guardrail rail being pivoted about the coupling element     of the first vertical post or frame.

The procedure enables the guardrail rail to be assembled from a lower scaffolding level or the formation of a leading guardrail. Accordingly, safety is increased during erection of the scaffold. After erection of the scaffolding, safety is further increased by the fact that the guardrail post cannot be dismantled. This is because dismantling requires the guardrail rail to be moved relative to the coupling elements of the vertical posts or frames. To do this, one of the two vertical posts or frames would first have to be dismantled. The guardrail post can only be dismantled successively with the dismantling or removal of the scaffolding.

In step a) and/or step b) of the method, i.e. when coupling a coupling section of the guardrail rail with a coupling element of a vertical post or frame, the coupling element of the vertical post or frame is preferably brought into engagement with the opening of the respective coupling section of the guardrail rail. Depending on the specific design of the opening of the coupling section and the coupling element, different procedures are possible.

The coupling member of the vertical stem or frame has preferably an L-shaped configuration and comprises a first section and a second section arranged at an angle to the first section. Further preferably, both sections each have a circular cross-sectional shape.

Provided that the coupling section to be coupled has an opening with an end-side extension which is guided up to a side edge of the coupling section, the railing member can be rotated in such a way that the coupling section is aligned vertically and the extension is arranged above the first section of the coupling element of the vertical post or frame. The coupling portion then only needs to be lowered so that the coupling member engages the opening via the extension. The railing member is then moved longitudinally so that the coupling member reaches the end of the opening which does not have an extension. In this position, the railing stile can no longer be unhooked, but can still be pivoted about the coupling element to transfer it to its position of use.

Provided that the coupling section to be coupled has an opening with an end extension which does not extend to a side edge of the coupling section, the procedure is slightly different. The railing member is first rotated such that the coupling section is oriented substantially horizontally and the extension is disposed above the second portion of the coupling member of the vertical post or frame. By lowering the coupling portion, the coupling member is then brought into engagement with the opening in the region of the extension. The railing member is then rotated about an axis parallel to its longitudinal axis until the coupling portion is aligned vertically. Subsequently, the railing spar is displaced so that the coupling member reaches the end of the opening which is not widened. This ensures that the railing member can no longer be unhooked. Optionally, after the coupling element has been inserted into the opening, the railing spar may first be displaced and then rotated. Moreover, the movements can be carried out simultaneously.

Since the proposed guardrail spar is particularly suitable for forming a leading guardrail, it is further proposed to use a guardrail spar according to the invention in a scaffold, in particular in a modular or frame scaffold, for forming a leading guardrail. The guardrail spar can be easily assembled from a lower scaffolding level or transferred to its position of use by means of a second vertical post or frame. Once the second vertical post or frame has been assembled, the guardrail post can no longer be dismantled. In this way, the highest safety requirements are met.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention and their advantages are explained in more detail below with reference to the accompanying figures. These show:

FIG. 1 a perspective view of a vertical post and rail of a modular scaffold,

FIG. 2 a top view of a vertical post with the handrail rail of FIG. 1 ,

FIG. 3 a perspective view of a modular scaffold having a plurality of vertical posts and guardrail rails corresponding to the guardrail rail of FIG. 1 ,

FIG. 4 a side view of the guardrail of FIG. 1 ,

FIG. 5 a side view of a second guardrail,

FIG. 6 a perspective view of a vertical post with a railing rail already assembled and a railing rail yet to be assembled, according to a third preferred embodiment of the invention,

FIG. 7 a perspective view of the vertical post and guardrail rails of FIG. 6 in advanced assembly, and

FIG. 8 a top view of a coupling portion of a guardrail rail according to FIGS. 6 and 7 .

DETAILED DESCRIPTION

FIG. 1 shows a first embodiment of a guardrail post 10 according to the invention in connection with a vertical post 30 of a modular scaffolding 100. In FIG. 1 , the vertical post 30 is in its position of use. In this position it is vertically aligned. On the outer circumferential side, the vertical stem 30 has a plurality of coupling elements 40 which are arranged at different height positions. The coupling elements 40 are each L-shaped, so that they form a kind of hook. In the region of a coupling element 40, the railing rail 10 is hooked. In this position, the railing post 10 can be connected to a further vertical post (not shown) and brought into its position of use with the aid of the latter (see FIG. 3 ). The further vertical post 30 is mounted at the same time. In this way, a forwardly extending railing can be formed.

The railing post 10 shown in FIG. 1 is made of a metal tube 13 which is plastically deformed at each of its two ends 11, 12 and has a coupling section 20. The coupling sections 20 (see FIG. 4 ) are each flat and have an opening 21. An extension 22 is provided at one end of the opening 21. Via the extension 22, the coupling element 40 can be brought into engagement with the opening 21 of the coupling section 20.

In particular, as can be seen from FIG. 2 , the opening 21 of the coupling portion 20 has a width b1, which is slightly greater than the diameter of the coupling element 40 outside a bead-like projection 43. Accordingly, the bead-like protrusion 43 is engaged behind by the coupling portion 20 of the railing spar 10 when the railing spar 10 is rotated from a position of use such that it assumes the position shown in FIG. 2 . Thus, the railing spar 10 cannot be unintentionally unhooked. To do so, the railing post 10 would first have to be displaced in such a way that the coupling element 40 reaches the other end of the opening 21, which has the extension 22. However, this is not possible in the position of use of the guardrail post 10 (see FIG. 3 ).

For easy hooking of the guardrail post 10, the extension 22 is a slot extending to a side edge 24 of the coupling section 20. Accordingly, the extension 22 opens the opening 21 towards the side edge 24. For easy threading of the coupling element 40, the extension 22 is chamfered on both sides in the region of the side edge 24. Apart from the extension 22, the opening 21 is arranged centrally with respect to the longitudinal axis A of the guardrail spar 10, so that webs of equal width are obtained on both sides, each having a width a1. The width a1 is slightly smaller than the distance between the coupling element 40 and the vertical post 30, allowing the guardrail post 10 to be rotated about its longitudinal axis A or an axis parallel thereto, if required, without the guardrail post 10 being unhinged.

As shown by way of example in FIG. 3 , the coupling elements 40 of the vertical posts 30 are designed to receive a plurality of, in particular two, guardrail posts 10. For this purpose, each coupling element 40 comprises a first section 41 and a second section 42 arranged at right angles to the first section 41. The second section 42 thereby extends vertically upwards. That is, the second section 42 extends parallel to the vertical stem 30. The second section 42 also forms the bead-like projection 43. In the position of use, the guardrail posts 10 are each supported by the first section 41 of the coupling element 40 so that the coupling sections 20 of the guardrail posts 10 are vertically aligned. Thus, two railing spars 10 can be arranged side by side. In this case, the coupling sections 20 of the two railing spars 10 lie flat on top of each other.

As can be seen from FIGS. 1 and 2 , the vertical posts 30 may have further coupling elements in the form of perforated discs 50. Scaffolding elements, such as decking ledgers, longitudinal ledgers and/or diagonal ledgers (not shown), can be attached to these. Decking ledgers serve to receive a scaffolding deck 61, which is shown by way of example in FIG. 3 .

In deviation from the embodiment of a railing spar 10 according to the invention shown in FIG. 4 , with two coupling sections 20 of identical design, a railing spar 10 according to the invention can also have two coupling sections 20 of different design. This is shown by way of example in FIG. 5 . The right-hand coupling section 20 is designed analogously to the coupling sections 20 of the embodiment of FIG. 4 . The left-hand coupling section 20, on the other hand, has an opening 21 without an extension 22 at the end. Variations of this design are quite possible.

Referring to FIGS. 6, 7 and 8 , a further preferred embodiment of a railing spar 10 according to the invention can be seen. FIGS. 6 and 7 each show a first guardrail rail 10 already connected to a coupling element 40 of a vertical post 30, and another guardrail rail 10 during assembly. As can be seen in particular from FIG. 8 , the coupling sections 20 of the railing posts 10 each have an opening 21 with an extension 22 at the end, which does not extend to a side edge 24 of the coupling section 20, but maintains a distance a2 from the two side edges 24 in each case. The extension 22 has a width b2, which, in principle, is greater than the width b1 of the opening 21. The width b2 of the extension 22 is adapted to the bead-like projection 43 of the coupling element 40, so that the coupling section 20 can be guided over the bead-like projection 43 during hooking-in. The coupling section 20 is thereby oriented substantially horizontally (see FIG. 6 ). Subsequently, by sliding, the coupling member 40 is guided from the region of the extension 22 to the other end of the opening 21 so that the coupling portion 20 engages behind the bead-like projection 43 of the coupling member 40. Beforehand or in the process, the coupling portion 20 may be brought into the vertical position by rotating the railing member 10. The coupling portion 20 thus comes to lie adjacent to the coupling portion 20 of the already assembled guardrail rail 10.

The rotation of the railing spar 10 requires a certain freedom of movement, which is created in the embodiment example of FIGS. 6 and 7 by the fact that the coupling section 20 has a width B2 at the end, which is reduced compared to a width B1 in the region of the connection to the metal tube 13 of the railing spar 10. For this purpose, the side edges 24 of the coupling section 20 each have a recess 23 (see also FIG. 8 ).

In order to enable the railing member 10 to be rotated and/or pivoted even in confined conditions, the coupling section 20 further comprises a circular arcuate end edge 25 connecting the two side edges 24. Since the circular arc-shaped course of the end edge 25 is formed concentrically with the circular arc-shaped course of the extension 22, the distance a2 of the extension 22 from the side edges 24 does not change even in the region of the end edge 25. This means that the same movement clearance is always required when pivoting the guardrail rail 10. The necessary freedom of movement is further provided by the fact that, in the embodiment of FIGS. 6 and 7 , the extension 22 of the opening 21 is arranged externally. This is because, if it were arranged on the inside, a collision would occur with the already assembled guardrail post 10, as exemplified in FIG. 7 .

An arcuate end edge 25, which is concentric with a curve at the end of the opening 21, is therefore also present in the coupling section 20 of the guardrail spar 10 of FIGS. 1 to 4 (see FIG. 2 ).

LIST OF REFERENCE SIGNS

-   10 guardrail -   11 first end of the guardrail -   12 second end of the guardrail -   13 metal tube -   20 coupling section -   21 opening -   22 expansion -   23 recess -   24 side edge -   25 front edge -   30 vertical handle -   40 coupling element -   41 first section of the coupling element -   42 second section of the coupling element -   43 protrusion -   50 perforated disc -   61 scaffolding decking -   100 scaffolding -   A longitudinal axis of the handrail -   B1 width of the coupling section -   B2 width of the coupling section -   a1 distance of the opening 21 to a side edge 24 -   a2 distance of the extension 22 to a side edge 24 -   b1 width of opening 21 -   b2 width of extension 22 

1. A guardrail for a scaffold, having at least at one end a coupling portion for coupling to a coupling member of a vertical post or of a vertical frame of the scaffold, wherein the coupling portion is flat and is penetrated by an elongate opening which extends parallel to a longitudinal axis of the railing spar, which has a constant width up to an end widening.
 2. The guardrail according to claim 1, wherein, in top view of the coupling portion, the opening and/or the extension is/are arranged centrally with respect to the longitudinal axis.
 3. The guardrail according to claim 1, wherein the end-side widening is arranged at the end of the opening facing the railing spar, wherein, in top view of the coupling section, the opening is widened on one side only.
 4. The guardrail according to claim 1, wherein, in top view of the coupling section, the extension is guided in a slot-like manner up to a side edge of the coupling section.
 5. The guardrail according to claim 1, wherein the end-side widening is arranged at the end of the opening facing away from the railing spar, wherein, in top view of the coupling section, the opening is widened on both sides, is formed mirror-symmetrically with respect to the longitudinal axis.
 6. The guardrail according to claim 5, wherein, in top view of the coupling section, the extension is rounded, circular or part-circular.
 7. The guardrail according to claim 5, wherein the coupling section has a reduced width at its end facing away from the railing spar, wherein, for reducing the width, the coupling section has a recess on both sides.
 8. The guardrail according to claim 1, wherein the coupling portion has, in top view, two straight side edges and an arcuate end edge connecting the two side edges, wherein the arcuate end edge is concentric with a rounding at the outer end of the opening.
 9. The guardrail according to claim 1, wherein the guardrail is formed from a metal tube which has a circular cross-sectional shape and/or is plastically deformed at least at one end to form or receive a coupling portion.
 10. The guardrail according to claim 1, wherein the guardrail has a coupling section at both ends and wherein the two coupling sections are of the same or of different design.
 11. A scaffolding having at least one guardrail according to claim 1 and at least one vertical post or vertical frame, which has at least one coupling element for coupling to a coupling section of the guardrail spar.
 12. The scaffolding according to claim 11, wherein the coupling element is substantially L-shaped and has a first section connected to the vertical stem or vertical frame and a second section arranged at right angles thereto, which second section extends vertically upwards in the position of use of the vertical stem or vertical frame.
 13. The scaffolding according to claim 12, wherein the first portion and the second portion of the coupling element each have a circular cross-sectional shape and/or the second portion has a bead-like projection which extends only over a partial circumferential region.
 14. The scaffolding according to claim 13, wherein the bead-like projection is arranged at least on the side of the second portion facing the vertical stem or the vertical frame, so that the distance between the second portion of the coupling element and the vertical stem or the vertical frame is reduced by the projection.
 15. A method of erecting a scaffold in which a guardrail according to claim 1 is connected to an already assembled first vertical post or frame and a second vertical post or frame yet to be assembled, comprising: a) coupling a first coupling portion of the guardrail rail to a coupling member of the first vertical post or frame, b) coupling a second coupling portion of the guardrail rail to a coupling member of the second vertical post or frame, c) positioning the railing post with the aid of the second vertical post or frame, which is moved into its position of use for this purpose, the railing post being pivoted about the coupling element of the first vertical post or frame.
 16. The method according to claim 15, wherein in step a) and/or in step b) the coupling element of the vertical post or frame is brought into engagement with the opening of the respective coupling portion of the railing rail.
 17. Use of a guardrail spar according to claim 1 in a scaffold, in a modular or frame scaffold, for forming a leading guardrail. 